It's TOTALLY over hyped in my opinion. It's one of the only films I wouldn't watch again (along with the Zombie Diaries, but that's another story!!!!!). It's got nothing in it to make me want to watch it again, sure it's a totally sick concept but it's a total waste of film in my eyes, wasn't scary or over the top gory.
I wouldn't even class it as a horror movie, I haven't seen the sequel and don't have any desire too, not that I'll ever get chance with my nanny government deciding what I should be allowed to watch anyway.